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By Geoffrey G. Hunkin

This is a brief state of the art paper describing current (1975) Uranium recovery plant flowsheets, some notes on system selection, design philosophies, and materials of construction. The in-situ, or borehole solution mining, of Uranium is a process which has been developed over recent years to better match Uranium mining and milling technology with the size, shape, grade and territorial distribution of the remaining identified Uranium deposits of western United States. Solution mining recovery plants are pure hydrometallurgical units ideally suited to automation, modular design, and mobility. Similar to conventional Uranium mills, two basic flowsheets, one acid and one carbonate, are in use, but the predominance is reversed so that the majority of plants employ the alkaline carbonate flowsheet, All plants incorporate resin bead ion exchange Uranium recovery for both acid and alkaline circuits.

Jan 1, 1976

By J. A. Organiscak

This paper describes the research con-ducted on bit wear and respirable dust generation conducted by the US Bureau of Mines (USBM) and West Virginia University (WVU), a member of the Generic Technology Center on Respirable Dust. The USBM investigated wear, energy and dust characteristics of various conical bit designs when cutting rock. WVU studied the functional relationships between wear, cutting force, energy, and dust of one conical bit type when cutting coal. The objective of the USBM study was to identify qualitative bit selection guidelines for cut-ting rock; WVU's research objective was to determine optimum bit replacement guidelines. These research studies both found that bit geometry (a function of bit design and wear) influences energy consumption and dust generation. Bit selection and replacement recommendations are given.

Jan 1, 1995

By T. M. Ruff, W. G. McCoy, M. J. Beus, S. Iverson, W. Hasz

Technology to enhance safety during mine hoisting has been developed by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Assessment of current hoisting technology suggests that monitoring conveyance position and load directly from the skip or cage top offers several significant safety advantages. Wireless data transmission schemes and a package consisting of sensors, batteries, and a charger mounted on the wire rope and skip have been developed. A state-of-the-art automated hoisting test facility was constructed to test the concept in a controlled laboratory setting. Field tests in a full-size shaft are underway.

Jan 1, 1999

By Robert H. Carpenter

Abstract, Syngenetic uranium in pre metamorphic Idaho Springs volcanics and sediments probably, was mobilized during metamorphism (1.7 b.y.) and partly retained along unconformities. Precambrian Silver Plume intrusives (1.4 b.y.) and Pikes Peak granite (1.0 b.y.) may have mobilized uranium from the craton and. Idaho Springs metamorphics to concentrate it in cauldron sites in migmatites, pegmatites, alaskite, disseminations and greissen. Tertiary intrusives also may have upgraded uranium by anatexis, leaching and differentiation. Tertiary vein and shear zone uranium mineralization may have-been-derived from underlying magma sources, leached from Idaho Springs metamorphics and from syngenetic leaching of overlying sediments and introduced by deep hydrothermal convection systems.

Jan 1, 1979

By Wilfred M. Kenan

The relationship of various genetic classifications of graphite, their properties and general applications are reviewed. The classifications being amorphous, flake, high crystalline (vein) primary synthetic graphite and secondary graphite. The properties discussed are size, carbon, sulfur, ash content, general chemical analysis and degree of graphitization of each type. The major sources for natural and synthetic graphite powders are discussed in addition to factors which govern the cost as well as the supply. The economics of graphite are basically determined by the consumer and the end application. Graphite is a strategic mineral and is on the government stockpile list.

Jan 1, 1984

By S. Dubnewych, S. Kieffer, M. T. McRae, R. R. Redd

The seismic vulnerability of the existing outlet tower at Lake Mathews reservoir, located in Riverside County, California, necessitated the design of a new outlet facility to assure serviceability of the facility following a major earthquake. The components of the proposed facility include: a new outlet tower; a shaft; a new outlet tunnel; an approach channel that will be excavated underwater; and two short tunnels that will connect the new outlet tunnel to the existing outlet tunnel via the shaft. As the new facilities will be constructed while the reservoir is in operation, a cofferdam will be constructed around the site of the new outlet tower. The design for the underground facilities used a combination of empirical methods; limit equilibrium analyses, including displacement-based pseudo-static analyses for dynamic loading conditions; and numerical analyses. This paper outlines the design methodology used to develop an innovative design for the facilities which can be constructed within the time frame required by the operational schedule of the reservoir and existing outlet facility.

Jan 1, 1999

By M. S. Frasad

The State of Minnesota is interested in stimulating the development of clay resources and recently supported a two year project to collect data on geological, mineralogical, processing, economic and environmental aspects of such potential developments. This paper presents the .various process options adopted on the bulk samples collected from the Minnesota River Valley area which is a primary deposit and contains a major silica fraction. A standard test flowsheet involving degritting, dispersion, HGMS, and cycloning was developed and for some samples yielded an acceptable filler grade product. Secondary streams containing relatively high grade kaolin but of coarse size were also obtained. Improvement in particle size distribution and in physical properties related to paper product specifications (brightness, viscosity) were obtained by size reduction processes. Market and economic considerations for kaolin consumption in the upper Midwest are analyzed. Current markets for paper grade kaolin in Minnesota were briefly discussed.

Jan 1, 1990

By A. I. Johnson

The pegmatites of the Black Hills of South Dakota are the coarse-grained differentiates of the Harney Peak Granite. The Harney Peak Granite was intruded into the Pre-cambrian schist and quartzites and resulted in the Black Hills uplift. In the outer adzes of the granite intrusion occur the pegmatites. In the zoned pegmatites, representing the most highly differentiated portions of the parent magma, occur most of the minerals produced from pegmatites. These are of economic importance and they are the subject of this paper. The various mineral products will be taken up separately.

Jan 1, 1978

By L. G. Closs

Gold continued to be the primary focus of minerals exploration worldwide during 1995. Other targets, though, included primary diamonds and base metals, especially copper deposits amenable to solvent-extraction/electrowinning (SX/EW) processing. The discovery of nickel, copper and cobalt at Voisey Bay in Labrador, Canada was an unusual surprise. Meanwhile, exploration geochemistry continues to evolve to meet new challenges. The major event in this category during 1995 was the17th International Geochemical Exploration Symposium (IGES) held in Townsville, Queensland, Australia in May. The meeting was sponsored by the Association of Exploration Geochemists, which celebrated its 25thanniversary of service to the mineral industry, and the Economic Geology Research Unit of James Cook University, Townsville.

Jan 1, 1996

By T. S. Govindan

The first step in energy conservation in any industrial plant involves implementing many of the day-to-day "house-keeping" items such as fixing leaks, turning out lights, etc. When this step has been accomplished, additional opportunities require a detailed analysis of the energy systems, evaluation of risks and costs, and assignment of priorities. Examples of conservation schemes drawn from the experience of Du pont's Energy Management Consulting Services will be discussed. The utility of heat balances for kilns and dryers in minerals processing will be outlined. The inputs needed from Management for the success of conservation efforts will be discussed.

Jan 1, 1978

By Elisabeth Tønnesen, Lloyd Tunbridge

"SUMMARY Injection grouting in rock around tunnels is used to reduce or stop water inflow. Little is known about the distribution of pressure within the rock mass during and after grouting. Instrumentation was developed to record pressure at the back of the packers inside the rock mass during injection grouting in order to improve our understanding of the process. Using this equipment measurements inside multiple injection holes during injection pumping have been made during several rounds of injection grouting in a tunnel. The data has been compared to the data recorded on the grout pumping rig and analysed to gain an understanding of the behaviour of grout injection process in the rock mass. The initial results are reported in this paper. INTRODUCTION Construction of a tunnel in soil or rock below the ground water table frequently results in the flow of ground water into the tunnel if the ground is permeable or fractures conductive. The injection of cement or chemical based grouts is frequently used during tunnel construction to reduce flow of water into a tunnel. Significant water flow into a tunnel is undesirable for several reasons: • there is a high cost in pumping out water over the lifetime of a tunnel; • drips and flows of water have to be diverted from the roadway or track; • where freezing conditions occur there is the possibility of ice build up and; • ground water levels may be changed possibly affecting surface water such as causing drainage of lakes and ponds, and changes in vegetation. Grout injection is most effectively done ahead of excavation to ensure that the grout penetrates the ground. Where heavy flows of water already occur into a tunnel the grout may be washed out before it sets. Normal practice in ground where water flows are encountered is to inject grout in a number of long holes ahead of the face with outer holes forming a ring around the proposed tunnel excavation – eventually forming a shield of grouted rock around the final tunnel, Figure 1. The holes may be sealed off a couple of metres into the rock with an expandable rubber plug around a pipe through which the grout can be injected, Figure 2. A one-way valve in the plug stops the grout from flowing back out of the hole when pumping stops and avoids grout flowing out through neighbouring holes. The rubber packer with a one-way valve permanently installed in the injection hole precludes the measurement of pressure down the hole when pumping is stopped."

Jan 1, 2016

By E. B. Kroeger

Spoil instability has been a problem at a coal mine in interior Alaska. Parameters such as original site topography, groundwater conditions, material properties, spoil-pile geometry, geology, permafrost, natural slope instability, changing weather conditions, and dense, near-surface vegetation have interacted to produce unstable slopes. Several failure modes have been identified including deep seated earth block slides, bimodal earth flows, and solifluction. Thawing of permafrost also created conditions where sliding of spoil along the interface separating the spoil and the natural ground surface occurred when the cohesion and the friction angle of that zone was reduced to zero and below 15?respectively.

Jan 1, 1992

By Neal Cochran

I consider it a distinct privilege to be afforded the opportunity of discussing the program of the Office of Coal Research. The principal activities I will be discussing are concerned with projects that fall in the utilization area. I will, to be sure, touch on other activities of the Office of Coal Research but am not equipped to discuss these activities in great detail. Research activities of the Office of Coal Research are conducted on a contract basis with commercial, academic, and non-profit institutions. We do not operate any laboratories of our own but we do maintain a very small staff for technical and administrative supervision of our contractors. We have consistently attempted to interest outstanding, creative, and practical research organizations in our program. We are constantly seeking the imaginative new idea that will materially reduce the cost of mining coal, transporting it, or will process it into a more convenient and useable form. In assessing proposals and in developing our program, we search for the improvements that will develop large-scale new uses for coal or coal products or those that support these new uses.

Jan 1, 1963

By John W. King

reserves are exploring to increase them.. Uranium exploration projects are known to be active or planned also in Guayana, Colombia, Ecuador, Peru, Chile, Bolivia, and Uruguay in South America; in the UAR, Nigeria, Angola, Mozambique, Malawi, Kenya, and Somali in Africa; and in Greece, Iran, Pakistan., Indonesia, and New Zealand. The above list, to which several might be added makes a total of at least 43 nations actively interested in exploration for nuclear raw materials. As we consider the distribution of the world's uranium resources, it is interesting to note that roughly one third of the total occurs in deposits that are economically dependant upon another product. The very large reserves of South Africa could not be produced for uranium alone, but gold has carried a sufficient part of the total cost that uranium can be recovered profitably. Approximately 40 percent of the US reserves, or 120,000 tons, are estimated as by-product recovery from porphyry copper and phosphate operations, but these reserves are not presently in production. The remaining two thirds of the world's uranium reserves have been sought, developed, and produced primarily for their uranium content. Those deposits are estimated to contain 613,000 tons of uranium oxide recoverable at less than $10 per pound. Nearly half of that uranium occurs in unmetamorphosed sandstone hosts, mostly of late Phanerozoic age--the Colorado Plateau type. About 30 percent is contained in the quartz pebble conglomerates of southern Ontario, Canada, and 20 percent is in magmatic-related deposits--veins, contact deposits, mineralized breccias, etc.

Jan 1, 1969

By D. Loy LeRoy

As we are all aware, the impacts of the 1977 Surface Mining Act and the implementing OSM Regulations require application of new, as well as existing, equipment and technologies. Our firm recently completed (June, 1979) a study for the Department of Energy titled "Analysis of the Impact of Public Law 95-87 on Mining Performance." The objective of the study was to analyze the impact of the Act and its regulations on mining performance in order to provide recommendations to alleviate the impacts identified, including identification of research needs. This paper presents some of the highlights of that report: projected cost increases; additional equipment needed for compliance; review of methods currently practiced or those which can be modified; and will focus particulary on equipment and technology applications.

Jan 1, 1980

By I. E. Odom

The rare magnesium-lithium clay mineral hectorite occurs at many places in the McDermitt caldera of Nevada-Oregon. Commercial development of several high purity deposits began in 1986. The hectorite was precipitated in a lake environment formed after collapse of the McDermitt caldera. Hectorite beds and lenses are associated with volcaniclastic sediments, limestones, dolomites, zeolites and locally sandy bentonites. The high purity deposits appear to be associated with hydrothermal areas. The hectorite consists of extremely small flake-shaped crystals, and Ca is the predominant exchangeable ion. Its color ranges from white to light green. Commercial uses developed to date include high brightness magnesium aluminum silicate products, organophilic clays, pulp retention, and ceramics. The MAS is used as a suspending agent, binder, stabilizer and thixotrope in aqueous solutions for cosmetics, household cleaners, pharmaceuticals and miscellaneous industrial applications. Organoclays are used in printing inks and paints.

Jan 1, 1992

Water contact angles in the air/water/francolite, fuel oil/water/francolite and fuel oil/water/quartz systems were measured to describe the wetting characteristics of these minerals. It was found that white francolite is more hydrophilic than black and tan francolite both in the absence and presence of fatty acid addition. The contact angle measurement results do not correlate very well with the flotation response and it appears that kinetic aspects of the bubble attachment process play an important role in the francolite-fatty acid flotation system.

Jan 1, 1997

By A. B. Cecala

The Bureau of Mines has been performing research to lower the dust exposure of workers at mineral processing operations for a number of years. This research has mainly been directed at source control techniques in an effort to lower a worker's dust exposure at a particular job function. In some cases, this control technology provided a carryover effect in lowering the exposure of workers at other locations, but for the most part had very little effect in lowering dust levels throughout an entire mill building. Recently, the Bureau became aware of several mineral processing operations having problems with high over-all mill dust levels. These operations were all using baghouse-type collectors to address their most serious dust contamination areas. Although these major dust sources were being controlled, there were numerous minor dust sources that were not. These minor dust sources were causing dust levels in these operations to gradually increase as the day or shift progressed. The intent of this work was to determine general guidelines and design criteria for operations that may be interested in implementing a total mill ventilation system. Most mill buildings can be considered a closed system and thus any dust that is not being controlled within the structure, will cause dust levels to gradually increase over the shift. A total mill ventilation system should be designed to draw clean make-up air in near the base of the mill. This air provides general purging and may clear some dust laden areas throughout the mill structure. This air should be discharged at or near the top of the structure, where it is not a contaminant to plant personnel working outside. Without this exhaust system, dust can exit the building through open doors, windows, etc., and contaminate outside plant workers. This dust can also be recirculated back into the mill building causing additional contamination problems. A total mill ventilation system is not a stand-alone technique, but is a supplemental technique to assist other localized dust control systems.

Jan 1, 1994

By Aurel Goodwin

I chose the title "Let's Clear the Air" for this afternoon's presentation because it has two meanings, the literal and the figurative. Most of you know what MSHA is. Most of you know what MSHA does. And, for the most part, most of you know why. What I hope to accomplish today is to "clear the air" around our health standards, to clarify for you how MSHA views its congressional mandate under Title I Section 101(a)(6), (7), and (9) of the Mine Safety and Health Act. Asbestos, silica, radiation, noise, welding fumes, carbon monoxide, lead, hydrogen sulfide, nitrogen dioxide - the list of physical and chemical hazards encountered in the metal and nonmetal mining industry is as diversified as the industry itself, possibly even more so. In addition, miners are often exposed to several of these health hazards simultaneously.

Jan 1, 1980

By Haydn H. Murray, Sam M. Pickering

The term kaolin is used here, in a commercial sense, for near- white clay deposits which are dominantly comprised of the mineral kaolinite, or for products refined from such deposits. The term "china clay" has been used in the past as a synonym for kaolin, a reference to its first being mined some 3000 years ago at a hill near Jauchau Fu, Jiangxi Province, China as a porcelain raw material. The name kaolin was derived from the Chinese Kauling, which means high ridge. For most modem industrial applications kaolin must be extensively refined and processed from the crude state to enhance whiteness, purity, and other important commercial characteristics. After such processing, kaolin ranks as one of the most valuable of industrial clays, and it is used to some extent in most manufactured consumer products. In 1991, the United States alone produced kaolin valued at $1,072,366,000. It is applied very widely as a pigment, filler, coater, extender, ceramic raw material, catalyst base, electrical insulator, and pharmaceutical. Some more prominent uses include paper filling and coating; paint, plastic, adhesive, and ink pigment; rubber reinforcing agent; ceramic raw material for porcelain, dinnerware, tile, and enamels; catalyst base for petroleum cracking and auto exhaust emission catalytic control devices; cosmetics base; and digestive coating remedy. Those properties of kaolin clay which make it suited to these applications are related to its physical, optical, mineralogical, and chemical nature.

Jan 1, 1994